关键词: 根田鼠, 交叉抚育, 体重, 日增长率, 性别差异

Abstract: The laboratory population of root vole (Microtus oeconomus) was founded by cross-fostering method. In order to test the effects of fostering on body weight development, body weights of offspring and fostered offspring were measured respectively. The results showed that: There was no significant difference in male vole body weights during different developmental periods (2 - 70 age in days). There was no significant difference in female vole body weight during developmental periods (2 - 16, 25 -70 age in days) apart from 18 and 20 age in days. Before 25 age in days,there were no significant differences in body weight between male and female voles in offspring and fostered offspring separately. The differences of body weight between different sexes reached to the significant level from 25 ages in days. With the increase of age in days, the descendant tendencies of increasing ratio per day were evident among 4 groups of root voles. The regress equations were non-linear. It indicated that the fostering experience had transient influence (3d ≤ T < 9 d)on female rather than on male voles. Sexual dimorphisms of body weight were formed at the age of about 25 days in offspring and fostered offspring. Increasing ratio per day of 4 groups of root voles showed similarly descending tendency.

Key words: Body weight, Cross-fostering, Increasing ratio per day, Root vole (Microtus oeconomus), Sexual difference